Serrata amphora, Boyer, 2008

Boyer, Franck, 2008, The genus Serrata Jousseaume, 1875 (Caenogastropoda: Marginellidae) in New Caledonia, Mémoires du Muséum national d'Histoire naturelle 196, pp. 389-436 : 410-411

Serrata amphora n. sp.

Fig. 32

TYPE MATERIAL. — Holotype (dd) MNHN 20612 .

TYPE LOCALITY. — Southern New Caledonia, 23°09’S, 167°11’E, 650-680 m [BIOCAL: stn DW 36] .

MATERIAL EXAMINED. — Southern New Caledonia. BIOCAL: stn DW 36, 23°09’S, 167°11’E, 650-680 m, 1 dd (holotype, Fig. 32) .

DISTRIBUTION. — Southern New Caledonia, one shell in 650-680 m.

DESCRIPTION. — Shell ovate subcylindrical, slender, solid, opaque. Protoconch paucispiral, small, slightly bulging, smooth. Spire moderate-sized, conical, whorls faintly convex. Aperture narrow, very oblique, widening weakly anteriorly and attenuated towards base. Base tapering. Outer lip thin, regular, subvertical. Shoulder sloping weakly, outer edge making an angle below shoulder, very weakly arched over its anterior two thirds, outer margin wide, thickened, rounded, not stepped, inner edge weakly oblique, bearing 18 medium-sized, subequal denticles, similar in size to the interspaces. Four thin columellar plaits, 2 anterior ones oblique, slightly sinuous, 2 posterior ones less oblique, decreasing in size posteriorly.

Ground colour whitish (faded), with faint wide pale orange markings on upper half and on base of outer margin.

Dimensions: 8.70 x 4.10 mm.

Radula unknown.

REMARKS. — Despite its larger size, the shell morphology of Serrata amphora is intermediate between S. hians and S. dentata in general outline, its columellar plaits are similar to those of these 2 species, and its labial denticles are similar to those of S. aureosa .

S. amphora differs from S. hians in its more slender shell and its subpyriform outline, its much narrower aperture and its more numerous and regular labial denticles. It differs from S. aureosa in its larger and more slender shell, its thinner and more oblique columellar plaits, its less reflected outer lip and its slightly narrower aperture. It differs from S. dentata in its larger shell and its subpyriform outline, its slightly narrower aperture, its more numerous and less spaced labial denticles. Serrata hians , S. dentata and S. aureosa occur in close proximity to S. amphora , but without any intergrading of shell morphology.

ETYMOLOGY. — Latin amphora (n., amphora), referring to the general outline of the shell, which suggests the classical shape of the antique amphora.